A conventional vehicle includes an assembly of panel structures, referred to collectively as a rocker or rocker panel, which fits below the base of the door openings and between the wheel wells. This same assembly may also be called a sill or a side sill.
There are a variety of techniques that may be used to fabricate and assemble the rocker panel of a car. For example, U.S. Pat. No. 4,471,992, issued 18 Sep. 1984, discloses a rocker that includes three separate panels; an outer panel, an inner panel, and a reinforcement panel interposed between the inner and outer panels. The upper and lower longitudinal edges of the three panels are welded together to form a single assembly.
U.S. Pat. No. 4,911,495, issued 27 Mar. 1990, discloses a lightweight, rigid rocker panel. The disclosed rocker includes inner and outer panels that are spot welded together along an upper joint and an outer side joint. The inner panel is thicker than the outer panel. The patent also describes a rocker panel cover, formed by injection molding in an exemplary embodiment, which may be attached to the outer rocker panel using clips or other means. The panel cover is designed to prevent rust formation on the rocker panels, including the outer side joint, by covering the outer and lower sides of the outer panel.
U.S. Patent Application Publication 2009/0261622, published 22 Oct. 2009, discloses another rocker panel design that is comprised of inner and outer sheet metal shells that are welded to one another. A stiffening member, for example using a rolled profile, is inserted into the rocker panel from an open end and then fastened in place.
Although a variety of techniques are known for fabricating and assembling the rocker panels of a vehicle, these fabrication processes are often relatively complex while yielding structures of limited rigidity. Accordingly, what is needed is a lightweight, high strength rocker panel that is easy to manufacture and provides improved torsional rigidity. The present invention provides such a rocker.